The Kama Sutra gives detailed instructions on how to spank it. Contemporary Italians touch it for luck before placing a bet. Americans are having it cosmetically enhanced at rates approaching breast enlargement surgery. The female butt, tush, culo, or derri- has always inspired awe, fantasy, and slavish devotion.Curiously, its primary purpose is functional rather than aesthetic: butts balance our bodies while running, according to biologists. But ask any pygophiliac-as fundament fans are clinically termed-and you-ll get the same answer: female hindquarters exist to please the eye, the hands, and parts south. A pert posterior causes instant arousal, as Zora Neale Hurston observed in Their Eyes Were Watching God: "The men noticed her firm buttocks like she had grape fruits in her hip pockets." Or, as rapper Sir Mix-a-lot proclaimed, "My anaconda don-t want none, unless you-ve got buns, hun."Having all but disappeared from western culture in the breast-obsessed second half of the 20th